Method for burning contaminated fuel

ABSTRACT

A fuel system for a gas turbine engine adapted to handle dirty fuel includes a separating device of a centrifuge-filter type through which fuel is supplied from a fuel pump to a fuel control which controls the operation of the engine. The centrifuge-filter has a swirl chamber with a tangential inlet, a central annular filter, and outlets both outside and inside of the filter. It discharges a large portion of the fuel substantially clean and a small portion bearing the dirt. The clean fuel flows through the fuel control to small diameter ports of fuel nozzles and, at higher fuel flow rates, through a resistance valve or valves to large area ports of the fuel nozzles. The dirty fuel flows to the large flow ports of the nozzles, by-passing the fuel control. Alternatively, the centrifuge-filter may be downstream of the fuel control. In either case, a line from adjacent the outer surface of the filter to the pump inlet or to the large area ports acts to clean the filter by recirculating or discharging the finer dirt which tends to accumulate on the filter at low fuel flow rates.

United States Patent [1 1 Sharpe MI Oct. 2, 1973 1 1 METHOD FOR BURNING CONTAMINATED FUEL [75] inventor: Cecil H. Sharpe, Brownsburg, 1nd. [731 Assignee: General Motors Corporation,

Detroit, Mich.

[22] Filed: Feb. 9, 1972 21 Appl. No.: 224,903

Related US. Application Data [60] Division of Ser. No. 82,573, Oct. 21, 1970, Pat, No. 3,658,249, which is a continuation-in-part of Ser. No. 752,820, Aug. 15, 1968, abandoned.

[52] US. Cl 431/2, 431/121, 210/73,

210/137 [51] Int. Cl. F231) 7/00 [58] Field of Search 110/7 S, 7 R; 431/2,

[56] References Cited UNITED STATES PATENTS 3,485,369 12/1969 Voorheis 120/69 3,393,650 7/1968 Daman et a1... 110/7 R 3,343,826 9/1967 Manny et al.... 431/121 X 3,360,199 12/1967 Sharpe 210/433 X 2,979,160 4/1961 Haas 210/73 X 3,229,650 1/1966 Reich] 110/7 R 3,229,651 l/1966 Wasp 110/7 R 3,291,184 12/1966 Varvel 431/121 FUEL m CONTROL 3,120,490 2/1964 Samson 210/433 X Primary Examiner-William F. ODea Assistant ExaminerWilliam C. Anderson Attorney-Paul Fitzpatrick et a1.

[57] ABSTRACT A fuel system for a gas turbine engine adapted to handle dirty fuel includes a separating device of a centrifuge-filter type through which fuel is supplied from a fuel pump to a fuel control which controls the operation of the engine. The centrifuge-filter has a swirl chamber with a tangential inlet, a central annular filter, and outlets both outside and inside of the filter. lt discharges a large portion of the fuel substantially clean and a small portion bearing the dirt. The clean fuel flows through the fuel control to small diameter ports of fuel nozzles and, at higher fuel flow rates, through a resistance valve or valves to large area ports of the fuel nozzles. The dirty fuel flows to the large flow ports of the nozzles, by-passing the fuel control. Alternatively, the centrifuge-filter may be downstream of the fuel control. in either case, a line from adjacent the outer surface of the filter to the pump inlet or to the large area ports acts to clean the filter by recirculating or discharging the finer dirt which tends to accumulate on the filter at low fuel flow rates.

6 Claims, 1 Drawing Figure METHOD FOR BURNING CONTAMINATED FUEL This application is a division of my U.S. Pat. application Ser. No. 82,573 filed Oct. 21, 1970 and now U.S. Pat. No. 3,658,249, which is a continuation-in-part of my abandoned U.S. Pat. application Ser. No. 752,820 filed Aug. 15, l968.

The invention herein described was made in the course of work under a contract with the Department of Defense.

SUMMARY OF THE INVENTION My invention is directed primarily to a method of handling fuel adapted to cope with contaminated or dirty fuel and to render combustion engines capable of operating for substantial periods of time on badly contaminated fuel.

The problem arises with engines such, for example, as gas turbine engines in which the fuel is mixed with air by spraying through a nozzle or nozzles which have ports of small diameter which are easily clogged by particles of foreign matter, which may be called dirt.

According to the preferred embodiment of my invention, the contaminated fuel supplied by a suitable pump is passed through any suitable device or system which acts to separate the fuel into a relatively large flow of substantially clean fuel and a relatively small flow of fuel bearing the larger particles of dirt and, as far as feasible, the smaller contaminant particles also. The clean fuel is supplied through the engine fuel control to the small port or ports of the fuel nozzle or nozzles, which are thus isolated from the dirt. The relatively small portion of dirty fuel, which preferably is controlled by a valve or orifice, flows directly to the large flow ports of the nozzles, by-passing the fuel control and being isolated from the small ports. As a result, the dirty fuel is burned in the combustion chamber of the engine and there is no problem of safety involved in storing or disposing of the contaminated fuel. Also, there is no problem of filter loading.

An object of the invention is to provide a method of burning dirt-contaminated fuel capable of satisfactorily using known and preferred fuel handling and spraying apparatus. A further object of the invention is to provide a process for burning dirt-contaminated fuel involving separating out a minor portion of the fuel bearing the more troublesome contaminants from the remainder, routing the two portions through at least partially separate courses to combustion apparatus, and burning the fuel therein.

DESCRIPTION OF THE DRAWING The FIGURE is a schematic diagram of a fuel supply system for a gas turbine engine.

DETAILED DESCRIPTION OF THE INVENTION The FIGURE illustrates the method claimed herein and apparatus suitable for employing the method of the invention.

For a complete description of preferred methods embodying my invention as claimed herein, reference is made to my U.S. Pat. No. 3,658,249 for Apparatus and Method for Burning Contaminated Fuel filed Oct. 21, 1970.

Reference is made to the entire specification and drawings of the said patent, substantially all of which constitute a disclosure of the invention claimed herein. The disclosure of the said patent is incorporated herein by reference and made a part hereof as if fully described herein.

1 claim:

I. A method of burning dirt-laden liquid fuel comprising separating the fuel into two portions, a first portion consisting of most of the fuel and little of the dirt and a second portion consisting of the remainder of the fuel and most of the dirt, supplying the first portion of the fuel to combustion apparatus intolerant of dirt, and supplying the second portion of the fuel to a combustion apparatus tolerant of dirt.

2. A method of nebulizing dirt-laden liquid fuel comprising separating the fuel into two portions, a first portion consisting of most of the fuel and litle of the dirt and a second portion consisting of the remainder of the fuel and most of the dirt, supplying the first portion of the fuel to nebulizing apparatus intolerant of dirt and supplying the second portion of the fuel to nebulizing apparatus tolerant of dirt.

3. A method of burning dirt-laden liquid fuel comprising separating the fuel into two portions, a first portion consisting of most of the fuel and little of the dirt and a second portion consisting of the remainder of the fuel and most of the dirt, supplying the first portion of the fuel to nebulizing device intolerant of dirt, supplying the second portion of the fuel to a nebulizing device tolerant of dirt, spraying the fuel from the said nebulizing devices into a combustion apparatus, and burning the fuel in the combustion apparatus.

4. A method of burning fuel containing a significant amount of particulate contaminants comprising supplying such fuel under pressure, controlling the rate of supply of the fuel, nebulizing the fuel, and burning the fuel in a combustion apparatus, including separating the fuel into a first portion consisting of a major portion of the fuel and an insubstantial portion of the particulate contaminants and a second portion consisting of the remainder of the fuel and particulate contaminants, nebulizing the first portion of the fuel into the combustion apparatus in part through means having a low tolerance for particulate contaminants, and nebulizing the second portion of the fuel into the combustion apparatus through means having a high tolerance for particulate contaminants.

5. A method of burning fuel containing a significant amount of particulate contaminants comprising supplying the fuel under pressure and burning the fuel in a combustion apparatus fueled by the supplying means, including nebulizing the fuel in the combustion apparatus, and including separating the fuel into two portions, a first portion consisting of a major portion of the fuel and an insignificant portion of the particulate contaminants and a second portion consisting of the remainder of the fuel and particulate contaminants, and including nebulizing only the first portion of the fuel in one part of a nebulizing apparatus of the combustion apparatus and nebulizing the second portion of the fuel and part of the second portion of the fuel in a second part of the nebulizing apparatus of the combustion apparatus.

6. A method as recited in claim 2 comprising also spraying the fuel from the said nebulizing apparatuses into a combustion apparatus.

$ i i =l 3 3 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3:762;855 Dated October 2, 1973 Inventort's) Cecil rpe It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Page l, in the Abstract of the Disclosure, line 21, after 1 "rates." insert (Disclosure incorporated by reference to parent application Serial No. 82,573,

UQSI Non 0 Signed and sealed this 16th day of April 1971+.

(SEAL) Attest:

C MARSHALL DANN Commissioner of Patents EDWARD l LFLETCHERJR. Attesting Officer 

1. A method of burning dirt-laden liquid fuel comprising separating the fuel into two portions, a first portion consisting of most of the fuel and little of the dirt and a second portion consisting of the remainder of the fuel and most of the dirt, supplying the first portion of the fuel to combustion apparatus intolerant of dirt, and supplying the second portion of the fuel to a combustion apparatus tolerant of dirt.
 2. A method of nebulizing dirt-laden liquid fuel comprising separating the fuel into two portions, a first portion consisting of most of the fuel and litle of the dirt and a second portion consisting of the remainder of the fuel and most of the dirt, supplying the first portion of the fuel to nebulizing apparatus intolerant of dirt and supplying the second portion of the fuel to nebulizing apparatus tolerant of dirt.
 3. A method of burning dirt-laden liquid fuel comprising separating the fuel into two portions, a first portion consisting of most of the fuel and little of the dirt and a second portion consisting of the remainder of the fuel and most of the dirt, supplying the first portion of the fuel to nebulizing device intolerant of dirt, supplying the second portion of the fuel to a nebulizing device tolerant of dirt, spraying the fuel from the said nebulizing devices into a combustion apparatus, and burning the fuel in the combustion apparatus.
 4. A method of burning fuel containing a significant amount of particulate contaminants comprising supplying such fuel under pressure, controlling the rate of supply of the fuel, nebulizing the fuel, and burning the fuel in a combustion apparatus, including separating the fuel into a first portion consisting of a major portion of the fuel and an insubstantial portion of the particulate contaminants and a second portion consisting of the remainder of the fuel and particulate contaminants, nebulizing the first portion of the fuel into the combustion apparatus in part through means having a low tolerance for particulate contaminants, and nebulizing the second portion of the fuel into the combustion apparatus through means having a high tolerance for particulate contaminants.
 5. A method of burning fuel containing a significant amount of particulate contaminants comprising supplying the fuel under pressure and burning the fuel in a combustion apparatus fueled by the supplying means, including nebulizing the fuel in the combustion apparatus, and including separating the fuel into two portions, a first portion consisting of a major portion of the fuel and an insignificant portion of the particulate contaminants and a second portion consisting of the remainder of the fuel and particulate contaminants, and including nebulizing only the first portion of the fuel in one part of a nebulizing apparatus of the combustion apparatus and nebulizing the second porTion of the fuel and part of the second portion of the fuel in a second part of the nebulizing apparatus of the combustion apparatus.
 6. A method as recited in claim 2 comprising also spraying the fuel from the said nebulizing apparatuses into a combustion apparatus. 